1/* 2 * Copyright (C) 2011-2012 Red Hat, Inc. 3 * 4 * This file is released under the GPL. 5 */ 6 7#include "dm-thin-metadata.h" 8#include "persistent-data/dm-btree.h" 9#include "persistent-data/dm-space-map.h" 10#include "persistent-data/dm-space-map-disk.h" 11#include "persistent-data/dm-transaction-manager.h" 12 13#include <linux/list.h> 14#include <linux/device-mapper.h> 15#include <linux/workqueue.h> 16 17/*-------------------------------------------------------------------------- 18 * As far as the metadata goes, there is: 19 * 20 * - A superblock in block zero, taking up fewer than 512 bytes for 21 * atomic writes. 22 * 23 * - A space map managing the metadata blocks. 24 * 25 * - A space map managing the data blocks. 26 * 27 * - A btree mapping our internal thin dev ids onto struct disk_device_details. 28 * 29 * - A hierarchical btree, with 2 levels which effectively maps (thin 30 * dev id, virtual block) -> block_time. Block time is a 64-bit 31 * field holding the time in the low 24 bits, and block in the top 48 32 * bits. 33 * 34 * BTrees consist solely of btree_nodes, that fill a block. Some are 35 * internal nodes, as such their values are a __le64 pointing to other 36 * nodes. Leaf nodes can store data of any reasonable size (ie. much 37 * smaller than the block size). The nodes consist of the header, 38 * followed by an array of keys, followed by an array of values. We have 39 * to binary search on the keys so they're all held together to help the 40 * cpu cache. 41 * 42 * Space maps have 2 btrees: 43 * 44 * - One maps a uint64_t onto a struct index_entry. Which points to a 45 * bitmap block, and has some details about how many free entries there 46 * are etc. 47 * 48 * - The bitmap blocks have a header (for the checksum). Then the rest 49 * of the block is pairs of bits. With the meaning being: 50 * 51 * 0 - ref count is 0 52 * 1 - ref count is 1 53 * 2 - ref count is 2 54 * 3 - ref count is higher than 2 55 * 56 * - If the count is higher than 2 then the ref count is entered in a 57 * second btree that directly maps the block_address to a uint32_t ref 58 * count. 59 * 60 * The space map metadata variant doesn't have a bitmaps btree. Instead 61 * it has one single blocks worth of index_entries. This avoids 62 * recursive issues with the bitmap btree needing to allocate space in 63 * order to insert. With a small data block size such as 64k the 64 * metadata support data devices that are hundreds of terrabytes. 65 * 66 * The space maps allocate space linearly from front to back. Space that 67 * is freed in a transaction is never recycled within that transaction. 68 * To try and avoid fragmenting _free_ space the allocator always goes 69 * back and fills in gaps. 70 * 71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks 72 * from the block manager. 73 *--------------------------------------------------------------------------*/ 74 75#define DM_MSG_PREFIX "thin metadata" 76 77#define THIN_SUPERBLOCK_MAGIC 27022010 78#define THIN_SUPERBLOCK_LOCATION 0 79#define THIN_VERSION 2 80#define THIN_METADATA_CACHE_SIZE 64 81#define SECTOR_TO_BLOCK_SHIFT 3 82 83/* 84 * 3 for btree insert + 85 * 2 for btree lookup used within space map 86 */ 87#define THIN_MAX_CONCURRENT_LOCKS 5 88 89/* This should be plenty */ 90#define SPACE_MAP_ROOT_SIZE 128 91 92/* 93 * Little endian on-disk superblock and device details. 94 */ 95struct thin_disk_superblock { 96 __le32 csum; /* Checksum of superblock except for this field. */ 97 __le32 flags; 98 __le64 blocknr; /* This block number, dm_block_t. */ 99 100 __u8 uuid[16]; 101 __le64 magic; 102 __le32 version; 103 __le32 time; 104 105 __le64 trans_id; 106 107 /* 108 * Root held by userspace transactions. 109 */ 110 __le64 held_root; 111 112 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 113 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 114 115 /* 116 * 2-level btree mapping (dev_id, (dev block, time)) -> data block 117 */ 118 __le64 data_mapping_root; 119 120 /* 121 * Device detail root mapping dev_id -> device_details 122 */ 123 __le64 device_details_root; 124 125 __le32 data_block_size; /* In 512-byte sectors. */ 126 127 __le32 metadata_block_size; /* In 512-byte sectors. */ 128 __le64 metadata_nr_blocks; 129 130 __le32 compat_flags; 131 __le32 compat_ro_flags; 132 __le32 incompat_flags; 133} __packed; 134 135struct disk_device_details { 136 __le64 mapped_blocks; 137 __le64 transaction_id; /* When created. */ 138 __le32 creation_time; 139 __le32 snapshotted_time; 140} __packed; 141 142struct dm_pool_metadata { 143 struct hlist_node hash; 144 145 struct block_device *bdev; 146 struct dm_block_manager *bm; 147 struct dm_space_map *metadata_sm; 148 struct dm_space_map *data_sm; 149 struct dm_transaction_manager *tm; 150 struct dm_transaction_manager *nb_tm; 151 152 /* 153 * Two-level btree. 154 * First level holds thin_dev_t. 155 * Second level holds mappings. 156 */ 157 struct dm_btree_info info; 158 159 /* 160 * Non-blocking version of the above. 161 */ 162 struct dm_btree_info nb_info; 163 164 /* 165 * Just the top level for deleting whole devices. 166 */ 167 struct dm_btree_info tl_info; 168 169 /* 170 * Just the bottom level for creating new devices. 171 */ 172 struct dm_btree_info bl_info; 173 174 /* 175 * Describes the device details btree. 176 */ 177 struct dm_btree_info details_info; 178 179 struct rw_semaphore root_lock; 180 uint32_t time; 181 dm_block_t root; 182 dm_block_t details_root; 183 struct list_head thin_devices; 184 uint64_t trans_id; 185 unsigned long flags; 186 sector_t data_block_size; 187 bool read_only:1; 188 189 /* 190 * Set if a transaction has to be aborted but the attempt to roll back 191 * to the previous (good) transaction failed. The only pool metadata 192 * operation possible in this state is the closing of the device. 193 */ 194 bool fail_io:1; 195 196 /* 197 * Reading the space map roots can fail, so we read it into these 198 * buffers before the superblock is locked and updated. 199 */ 200 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 201 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 202}; 203 204struct dm_thin_device { 205 struct list_head list; 206 struct dm_pool_metadata *pmd; 207 dm_thin_id id; 208 209 int open_count; 210 bool changed:1; 211 bool aborted_with_changes:1; 212 uint64_t mapped_blocks; 213 uint64_t transaction_id; 214 uint32_t creation_time; 215 uint32_t snapshotted_time; 216}; 217 218/*---------------------------------------------------------------- 219 * superblock validator 220 *--------------------------------------------------------------*/ 221 222#define SUPERBLOCK_CSUM_XOR 160774 223 224static void sb_prepare_for_write(struct dm_block_validator *v, 225 struct dm_block *b, 226 size_t block_size) 227{ 228 struct thin_disk_superblock *disk_super = dm_block_data(b); 229 230 disk_super->blocknr = cpu_to_le64(dm_block_location(b)); 231 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 232 block_size - sizeof(__le32), 233 SUPERBLOCK_CSUM_XOR)); 234} 235 236static int sb_check(struct dm_block_validator *v, 237 struct dm_block *b, 238 size_t block_size) 239{ 240 struct thin_disk_superblock *disk_super = dm_block_data(b); 241 __le32 csum_le; 242 243 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { 244 DMERR("sb_check failed: blocknr %llu: " 245 "wanted %llu", le64_to_cpu(disk_super->blocknr), 246 (unsigned long long)dm_block_location(b)); 247 return -ENOTBLK; 248 } 249 250 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) { 251 DMERR("sb_check failed: magic %llu: " 252 "wanted %llu", le64_to_cpu(disk_super->magic), 253 (unsigned long long)THIN_SUPERBLOCK_MAGIC); 254 return -EILSEQ; 255 } 256 257 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 258 block_size - sizeof(__le32), 259 SUPERBLOCK_CSUM_XOR)); 260 if (csum_le != disk_super->csum) { 261 DMERR("sb_check failed: csum %u: wanted %u", 262 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); 263 return -EILSEQ; 264 } 265 266 return 0; 267} 268 269static struct dm_block_validator sb_validator = { 270 .name = "superblock", 271 .prepare_for_write = sb_prepare_for_write, 272 .check = sb_check 273}; 274 275/*---------------------------------------------------------------- 276 * Methods for the btree value types 277 *--------------------------------------------------------------*/ 278 279static uint64_t pack_block_time(dm_block_t b, uint32_t t) 280{ 281 return (b << 24) | t; 282} 283 284static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t) 285{ 286 *b = v >> 24; 287 *t = v & ((1 << 24) - 1); 288} 289 290static void data_block_inc(void *context, const void *value_le) 291{ 292 struct dm_space_map *sm = context; 293 __le64 v_le; 294 uint64_t b; 295 uint32_t t; 296 297 memcpy(&v_le, value_le, sizeof(v_le)); 298 unpack_block_time(le64_to_cpu(v_le), &b, &t); 299 dm_sm_inc_block(sm, b); 300} 301 302static void data_block_dec(void *context, const void *value_le) 303{ 304 struct dm_space_map *sm = context; 305 __le64 v_le; 306 uint64_t b; 307 uint32_t t; 308 309 memcpy(&v_le, value_le, sizeof(v_le)); 310 unpack_block_time(le64_to_cpu(v_le), &b, &t); 311 dm_sm_dec_block(sm, b); 312} 313 314static int data_block_equal(void *context, const void *value1_le, const void *value2_le) 315{ 316 __le64 v1_le, v2_le; 317 uint64_t b1, b2; 318 uint32_t t; 319 320 memcpy(&v1_le, value1_le, sizeof(v1_le)); 321 memcpy(&v2_le, value2_le, sizeof(v2_le)); 322 unpack_block_time(le64_to_cpu(v1_le), &b1, &t); 323 unpack_block_time(le64_to_cpu(v2_le), &b2, &t); 324 325 return b1 == b2; 326} 327 328static void subtree_inc(void *context, const void *value) 329{ 330 struct dm_btree_info *info = context; 331 __le64 root_le; 332 uint64_t root; 333 334 memcpy(&root_le, value, sizeof(root_le)); 335 root = le64_to_cpu(root_le); 336 dm_tm_inc(info->tm, root); 337} 338 339static void subtree_dec(void *context, const void *value) 340{ 341 struct dm_btree_info *info = context; 342 __le64 root_le; 343 uint64_t root; 344 345 memcpy(&root_le, value, sizeof(root_le)); 346 root = le64_to_cpu(root_le); 347 if (dm_btree_del(info, root)) 348 DMERR("btree delete failed\n"); 349} 350 351static int subtree_equal(void *context, const void *value1_le, const void *value2_le) 352{ 353 __le64 v1_le, v2_le; 354 memcpy(&v1_le, value1_le, sizeof(v1_le)); 355 memcpy(&v2_le, value2_le, sizeof(v2_le)); 356 357 return v1_le == v2_le; 358} 359 360/*----------------------------------------------------------------*/ 361 362static int superblock_lock_zero(struct dm_pool_metadata *pmd, 363 struct dm_block **sblock) 364{ 365 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION, 366 &sb_validator, sblock); 367} 368 369static int superblock_lock(struct dm_pool_metadata *pmd, 370 struct dm_block **sblock) 371{ 372 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 373 &sb_validator, sblock); 374} 375 376static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result) 377{ 378 int r; 379 unsigned i; 380 struct dm_block *b; 381 __le64 *data_le, zero = cpu_to_le64(0); 382 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64); 383 384 /* 385 * We can't use a validator here - it may be all zeroes. 386 */ 387 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b); 388 if (r) 389 return r; 390 391 data_le = dm_block_data(b); 392 *result = 1; 393 for (i = 0; i < block_size; i++) { 394 if (data_le[i] != zero) { 395 *result = 0; 396 break; 397 } 398 } 399 400 return dm_bm_unlock(b); 401} 402 403static void __setup_btree_details(struct dm_pool_metadata *pmd) 404{ 405 pmd->info.tm = pmd->tm; 406 pmd->info.levels = 2; 407 pmd->info.value_type.context = pmd->data_sm; 408 pmd->info.value_type.size = sizeof(__le64); 409 pmd->info.value_type.inc = data_block_inc; 410 pmd->info.value_type.dec = data_block_dec; 411 pmd->info.value_type.equal = data_block_equal; 412 413 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info)); 414 pmd->nb_info.tm = pmd->nb_tm; 415 416 pmd->tl_info.tm = pmd->tm; 417 pmd->tl_info.levels = 1; 418 pmd->tl_info.value_type.context = &pmd->bl_info; 419 pmd->tl_info.value_type.size = sizeof(__le64); 420 pmd->tl_info.value_type.inc = subtree_inc; 421 pmd->tl_info.value_type.dec = subtree_dec; 422 pmd->tl_info.value_type.equal = subtree_equal; 423 424 pmd->bl_info.tm = pmd->tm; 425 pmd->bl_info.levels = 1; 426 pmd->bl_info.value_type.context = pmd->data_sm; 427 pmd->bl_info.value_type.size = sizeof(__le64); 428 pmd->bl_info.value_type.inc = data_block_inc; 429 pmd->bl_info.value_type.dec = data_block_dec; 430 pmd->bl_info.value_type.equal = data_block_equal; 431 432 pmd->details_info.tm = pmd->tm; 433 pmd->details_info.levels = 1; 434 pmd->details_info.value_type.context = NULL; 435 pmd->details_info.value_type.size = sizeof(struct disk_device_details); 436 pmd->details_info.value_type.inc = NULL; 437 pmd->details_info.value_type.dec = NULL; 438 pmd->details_info.value_type.equal = NULL; 439} 440 441static int save_sm_roots(struct dm_pool_metadata *pmd) 442{ 443 int r; 444 size_t len; 445 446 r = dm_sm_root_size(pmd->metadata_sm, &len); 447 if (r < 0) 448 return r; 449 450 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len); 451 if (r < 0) 452 return r; 453 454 r = dm_sm_root_size(pmd->data_sm, &len); 455 if (r < 0) 456 return r; 457 458 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len); 459} 460 461static void copy_sm_roots(struct dm_pool_metadata *pmd, 462 struct thin_disk_superblock *disk) 463{ 464 memcpy(&disk->metadata_space_map_root, 465 &pmd->metadata_space_map_root, 466 sizeof(pmd->metadata_space_map_root)); 467 468 memcpy(&disk->data_space_map_root, 469 &pmd->data_space_map_root, 470 sizeof(pmd->data_space_map_root)); 471} 472 473static int __write_initial_superblock(struct dm_pool_metadata *pmd) 474{ 475 int r; 476 struct dm_block *sblock; 477 struct thin_disk_superblock *disk_super; 478 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT; 479 480 if (bdev_size > THIN_METADATA_MAX_SECTORS) 481 bdev_size = THIN_METADATA_MAX_SECTORS; 482 483 r = dm_sm_commit(pmd->data_sm); 484 if (r < 0) 485 return r; 486 487 r = save_sm_roots(pmd); 488 if (r < 0) 489 return r; 490 491 r = dm_tm_pre_commit(pmd->tm); 492 if (r < 0) 493 return r; 494 495 r = superblock_lock_zero(pmd, &sblock); 496 if (r) 497 return r; 498 499 disk_super = dm_block_data(sblock); 500 disk_super->flags = 0; 501 memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); 502 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC); 503 disk_super->version = cpu_to_le32(THIN_VERSION); 504 disk_super->time = 0; 505 disk_super->trans_id = 0; 506 disk_super->held_root = 0; 507 508 copy_sm_roots(pmd, disk_super); 509 510 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 511 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 512 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE); 513 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT); 514 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size); 515 516 return dm_tm_commit(pmd->tm, sblock); 517} 518 519static int __format_metadata(struct dm_pool_metadata *pmd) 520{ 521 int r; 522 523 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 524 &pmd->tm, &pmd->metadata_sm); 525 if (r < 0) { 526 DMERR("tm_create_with_sm failed"); 527 return r; 528 } 529 530 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0); 531 if (IS_ERR(pmd->data_sm)) { 532 DMERR("sm_disk_create failed"); 533 r = PTR_ERR(pmd->data_sm); 534 goto bad_cleanup_tm; 535 } 536 537 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 538 if (!pmd->nb_tm) { 539 DMERR("could not create non-blocking clone tm"); 540 r = -ENOMEM; 541 goto bad_cleanup_data_sm; 542 } 543 544 __setup_btree_details(pmd); 545 546 r = dm_btree_empty(&pmd->info, &pmd->root); 547 if (r < 0) 548 goto bad_cleanup_nb_tm; 549 550 r = dm_btree_empty(&pmd->details_info, &pmd->details_root); 551 if (r < 0) { 552 DMERR("couldn't create devices root"); 553 goto bad_cleanup_nb_tm; 554 } 555 556 r = __write_initial_superblock(pmd); 557 if (r) 558 goto bad_cleanup_nb_tm; 559 560 return 0; 561 562bad_cleanup_nb_tm: 563 dm_tm_destroy(pmd->nb_tm); 564bad_cleanup_data_sm: 565 dm_sm_destroy(pmd->data_sm); 566bad_cleanup_tm: 567 dm_tm_destroy(pmd->tm); 568 dm_sm_destroy(pmd->metadata_sm); 569 570 return r; 571} 572 573static int __check_incompat_features(struct thin_disk_superblock *disk_super, 574 struct dm_pool_metadata *pmd) 575{ 576 uint32_t features; 577 578 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP; 579 if (features) { 580 DMERR("could not access metadata due to unsupported optional features (%lx).", 581 (unsigned long)features); 582 return -EINVAL; 583 } 584 585 /* 586 * Check for read-only metadata to skip the following RDWR checks. 587 */ 588 if (get_disk_ro(pmd->bdev->bd_disk)) 589 return 0; 590 591 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP; 592 if (features) { 593 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", 594 (unsigned long)features); 595 return -EINVAL; 596 } 597 598 return 0; 599} 600 601static int __open_metadata(struct dm_pool_metadata *pmd) 602{ 603 int r; 604 struct dm_block *sblock; 605 struct thin_disk_superblock *disk_super; 606 607 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 608 &sb_validator, &sblock); 609 if (r < 0) { 610 DMERR("couldn't read superblock"); 611 return r; 612 } 613 614 disk_super = dm_block_data(sblock); 615 616 /* Verify the data block size hasn't changed */ 617 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) { 618 DMERR("changing the data block size (from %u to %llu) is not supported", 619 le32_to_cpu(disk_super->data_block_size), 620 (unsigned long long)pmd->data_block_size); 621 r = -EINVAL; 622 goto bad_unlock_sblock; 623 } 624 625 r = __check_incompat_features(disk_super, pmd); 626 if (r < 0) 627 goto bad_unlock_sblock; 628 629 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 630 disk_super->metadata_space_map_root, 631 sizeof(disk_super->metadata_space_map_root), 632 &pmd->tm, &pmd->metadata_sm); 633 if (r < 0) { 634 DMERR("tm_open_with_sm failed"); 635 goto bad_unlock_sblock; 636 } 637 638 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root, 639 sizeof(disk_super->data_space_map_root)); 640 if (IS_ERR(pmd->data_sm)) { 641 DMERR("sm_disk_open failed"); 642 r = PTR_ERR(pmd->data_sm); 643 goto bad_cleanup_tm; 644 } 645 646 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 647 if (!pmd->nb_tm) { 648 DMERR("could not create non-blocking clone tm"); 649 r = -ENOMEM; 650 goto bad_cleanup_data_sm; 651 } 652 653 __setup_btree_details(pmd); 654 return dm_bm_unlock(sblock); 655 656bad_cleanup_data_sm: 657 dm_sm_destroy(pmd->data_sm); 658bad_cleanup_tm: 659 dm_tm_destroy(pmd->tm); 660 dm_sm_destroy(pmd->metadata_sm); 661bad_unlock_sblock: 662 dm_bm_unlock(sblock); 663 664 return r; 665} 666 667static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device) 668{ 669 int r, unformatted; 670 671 r = __superblock_all_zeroes(pmd->bm, &unformatted); 672 if (r) 673 return r; 674 675 if (unformatted) 676 return format_device ? __format_metadata(pmd) : -EPERM; 677 678 return __open_metadata(pmd); 679} 680 681static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device) 682{ 683 int r; 684 685 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT, 686 THIN_METADATA_CACHE_SIZE, 687 THIN_MAX_CONCURRENT_LOCKS); 688 if (IS_ERR(pmd->bm)) { 689 DMERR("could not create block manager"); 690 return PTR_ERR(pmd->bm); 691 } 692 693 r = __open_or_format_metadata(pmd, format_device); 694 if (r) 695 dm_block_manager_destroy(pmd->bm); 696 697 return r; 698} 699 700static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd) 701{ 702 dm_sm_destroy(pmd->data_sm); 703 dm_sm_destroy(pmd->metadata_sm); 704 dm_tm_destroy(pmd->nb_tm); 705 dm_tm_destroy(pmd->tm); 706 dm_block_manager_destroy(pmd->bm); 707} 708 709static int __begin_transaction(struct dm_pool_metadata *pmd) 710{ 711 int r; 712 struct thin_disk_superblock *disk_super; 713 struct dm_block *sblock; 714 715 /* 716 * We re-read the superblock every time. Shouldn't need to do this 717 * really. 718 */ 719 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 720 &sb_validator, &sblock); 721 if (r) 722 return r; 723 724 disk_super = dm_block_data(sblock); 725 pmd->time = le32_to_cpu(disk_super->time); 726 pmd->root = le64_to_cpu(disk_super->data_mapping_root); 727 pmd->details_root = le64_to_cpu(disk_super->device_details_root); 728 pmd->trans_id = le64_to_cpu(disk_super->trans_id); 729 pmd->flags = le32_to_cpu(disk_super->flags); 730 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size); 731 732 dm_bm_unlock(sblock); 733 return 0; 734} 735 736static int __write_changed_details(struct dm_pool_metadata *pmd) 737{ 738 int r; 739 struct dm_thin_device *td, *tmp; 740 struct disk_device_details details; 741 uint64_t key; 742 743 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 744 if (!td->changed) 745 continue; 746 747 key = td->id; 748 749 details.mapped_blocks = cpu_to_le64(td->mapped_blocks); 750 details.transaction_id = cpu_to_le64(td->transaction_id); 751 details.creation_time = cpu_to_le32(td->creation_time); 752 details.snapshotted_time = cpu_to_le32(td->snapshotted_time); 753 __dm_bless_for_disk(&details); 754 755 r = dm_btree_insert(&pmd->details_info, pmd->details_root, 756 &key, &details, &pmd->details_root); 757 if (r) 758 return r; 759 760 if (td->open_count) 761 td->changed = 0; 762 else { 763 list_del(&td->list); 764 kfree(td); 765 } 766 } 767 768 return 0; 769} 770 771static int __commit_transaction(struct dm_pool_metadata *pmd) 772{ 773 int r; 774 size_t metadata_len, data_len; 775 struct thin_disk_superblock *disk_super; 776 struct dm_block *sblock; 777 778 /* 779 * We need to know if the thin_disk_superblock exceeds a 512-byte sector. 780 */ 781 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512); 782 783 r = __write_changed_details(pmd); 784 if (r < 0) 785 return r; 786 787 r = dm_sm_commit(pmd->data_sm); 788 if (r < 0) 789 return r; 790 791 r = dm_tm_pre_commit(pmd->tm); 792 if (r < 0) 793 return r; 794 795 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len); 796 if (r < 0) 797 return r; 798 799 r = dm_sm_root_size(pmd->data_sm, &data_len); 800 if (r < 0) 801 return r; 802 803 r = save_sm_roots(pmd); 804 if (r < 0) 805 return r; 806 807 r = superblock_lock(pmd, &sblock); 808 if (r) 809 return r; 810 811 disk_super = dm_block_data(sblock); 812 disk_super->time = cpu_to_le32(pmd->time); 813 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 814 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 815 disk_super->trans_id = cpu_to_le64(pmd->trans_id); 816 disk_super->flags = cpu_to_le32(pmd->flags); 817 818 copy_sm_roots(pmd, disk_super); 819 820 return dm_tm_commit(pmd->tm, sblock); 821} 822 823struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 824 sector_t data_block_size, 825 bool format_device) 826{ 827 int r; 828 struct dm_pool_metadata *pmd; 829 830 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL); 831 if (!pmd) { 832 DMERR("could not allocate metadata struct"); 833 return ERR_PTR(-ENOMEM); 834 } 835 836 init_rwsem(&pmd->root_lock); 837 pmd->time = 0; 838 INIT_LIST_HEAD(&pmd->thin_devices); 839 pmd->read_only = false; 840 pmd->fail_io = false; 841 pmd->bdev = bdev; 842 pmd->data_block_size = data_block_size; 843 844 r = __create_persistent_data_objects(pmd, format_device); 845 if (r) { 846 kfree(pmd); 847 return ERR_PTR(r); 848 } 849 850 r = __begin_transaction(pmd); 851 if (r < 0) { 852 if (dm_pool_metadata_close(pmd) < 0) 853 DMWARN("%s: dm_pool_metadata_close() failed.", __func__); 854 return ERR_PTR(r); 855 } 856 857 return pmd; 858} 859 860int dm_pool_metadata_close(struct dm_pool_metadata *pmd) 861{ 862 int r; 863 unsigned open_devices = 0; 864 struct dm_thin_device *td, *tmp; 865 866 down_read(&pmd->root_lock); 867 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 868 if (td->open_count) 869 open_devices++; 870 else { 871 list_del(&td->list); 872 kfree(td); 873 } 874 } 875 up_read(&pmd->root_lock); 876 877 if (open_devices) { 878 DMERR("attempt to close pmd when %u device(s) are still open", 879 open_devices); 880 return -EBUSY; 881 } 882 883 if (!pmd->read_only && !pmd->fail_io) { 884 r = __commit_transaction(pmd); 885 if (r < 0) 886 DMWARN("%s: __commit_transaction() failed, error = %d", 887 __func__, r); 888 } 889 890 if (!pmd->fail_io) 891 __destroy_persistent_data_objects(pmd); 892 893 kfree(pmd); 894 return 0; 895} 896 897/* 898 * __open_device: Returns @td corresponding to device with id @dev, 899 * creating it if @create is set and incrementing @td->open_count. 900 * On failure, @td is undefined. 901 */ 902static int __open_device(struct dm_pool_metadata *pmd, 903 dm_thin_id dev, int create, 904 struct dm_thin_device **td) 905{ 906 int r, changed = 0; 907 struct dm_thin_device *td2; 908 uint64_t key = dev; 909 struct disk_device_details details_le; 910 911 /* 912 * If the device is already open, return it. 913 */ 914 list_for_each_entry(td2, &pmd->thin_devices, list) 915 if (td2->id == dev) { 916 /* 917 * May not create an already-open device. 918 */ 919 if (create) 920 return -EEXIST; 921 922 td2->open_count++; 923 *td = td2; 924 return 0; 925 } 926 927 /* 928 * Check the device exists. 929 */ 930 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 931 &key, &details_le); 932 if (r) { 933 if (r != -ENODATA || !create) 934 return r; 935 936 /* 937 * Create new device. 938 */ 939 changed = 1; 940 details_le.mapped_blocks = 0; 941 details_le.transaction_id = cpu_to_le64(pmd->trans_id); 942 details_le.creation_time = cpu_to_le32(pmd->time); 943 details_le.snapshotted_time = cpu_to_le32(pmd->time); 944 } 945 946 *td = kmalloc(sizeof(**td), GFP_NOIO); 947 if (!*td) 948 return -ENOMEM; 949 950 (*td)->pmd = pmd; 951 (*td)->id = dev; 952 (*td)->open_count = 1; 953 (*td)->changed = changed; 954 (*td)->aborted_with_changes = false; 955 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks); 956 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id); 957 (*td)->creation_time = le32_to_cpu(details_le.creation_time); 958 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time); 959 960 list_add(&(*td)->list, &pmd->thin_devices); 961 962 return 0; 963} 964 965static void __close_device(struct dm_thin_device *td) 966{ 967 --td->open_count; 968} 969 970static int __create_thin(struct dm_pool_metadata *pmd, 971 dm_thin_id dev) 972{ 973 int r; 974 dm_block_t dev_root; 975 uint64_t key = dev; 976 struct disk_device_details details_le; 977 struct dm_thin_device *td; 978 __le64 value; 979 980 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 981 &key, &details_le); 982 if (!r) 983 return -EEXIST; 984 985 /* 986 * Create an empty btree for the mappings. 987 */ 988 r = dm_btree_empty(&pmd->bl_info, &dev_root); 989 if (r) 990 return r; 991 992 /* 993 * Insert it into the main mapping tree. 994 */ 995 value = cpu_to_le64(dev_root); 996 __dm_bless_for_disk(&value); 997 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 998 if (r) { 999 dm_btree_del(&pmd->bl_info, dev_root); 1000 return r; 1001 } 1002 1003 r = __open_device(pmd, dev, 1, &td); 1004 if (r) { 1005 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1006 dm_btree_del(&pmd->bl_info, dev_root); 1007 return r; 1008 } 1009 __close_device(td); 1010 1011 return r; 1012} 1013 1014int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev) 1015{ 1016 int r = -EINVAL; 1017 1018 down_write(&pmd->root_lock); 1019 if (!pmd->fail_io) 1020 r = __create_thin(pmd, dev); 1021 up_write(&pmd->root_lock); 1022 1023 return r; 1024} 1025 1026static int __set_snapshot_details(struct dm_pool_metadata *pmd, 1027 struct dm_thin_device *snap, 1028 dm_thin_id origin, uint32_t time) 1029{ 1030 int r; 1031 struct dm_thin_device *td; 1032 1033 r = __open_device(pmd, origin, 0, &td); 1034 if (r) 1035 return r; 1036 1037 td->changed = 1; 1038 td->snapshotted_time = time; 1039 1040 snap->mapped_blocks = td->mapped_blocks; 1041 snap->snapshotted_time = time; 1042 __close_device(td); 1043 1044 return 0; 1045} 1046 1047static int __create_snap(struct dm_pool_metadata *pmd, 1048 dm_thin_id dev, dm_thin_id origin) 1049{ 1050 int r; 1051 dm_block_t origin_root; 1052 uint64_t key = origin, dev_key = dev; 1053 struct dm_thin_device *td; 1054 struct disk_device_details details_le; 1055 __le64 value; 1056 1057 /* check this device is unused */ 1058 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 1059 &dev_key, &details_le); 1060 if (!r) 1061 return -EEXIST; 1062 1063 /* find the mapping tree for the origin */ 1064 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value); 1065 if (r) 1066 return r; 1067 origin_root = le64_to_cpu(value); 1068 1069 /* clone the origin, an inc will do */ 1070 dm_tm_inc(pmd->tm, origin_root); 1071 1072 /* insert into the main mapping tree */ 1073 value = cpu_to_le64(origin_root); 1074 __dm_bless_for_disk(&value); 1075 key = dev; 1076 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 1077 if (r) { 1078 dm_tm_dec(pmd->tm, origin_root); 1079 return r; 1080 } 1081 1082 pmd->time++; 1083 1084 r = __open_device(pmd, dev, 1, &td); 1085 if (r) 1086 goto bad; 1087 1088 r = __set_snapshot_details(pmd, td, origin, pmd->time); 1089 __close_device(td); 1090 1091 if (r) 1092 goto bad; 1093 1094 return 0; 1095 1096bad: 1097 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1098 dm_btree_remove(&pmd->details_info, pmd->details_root, 1099 &key, &pmd->details_root); 1100 return r; 1101} 1102 1103int dm_pool_create_snap(struct dm_pool_metadata *pmd, 1104 dm_thin_id dev, 1105 dm_thin_id origin) 1106{ 1107 int r = -EINVAL; 1108 1109 down_write(&pmd->root_lock); 1110 if (!pmd->fail_io) 1111 r = __create_snap(pmd, dev, origin); 1112 up_write(&pmd->root_lock); 1113 1114 return r; 1115} 1116 1117static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev) 1118{ 1119 int r; 1120 uint64_t key = dev; 1121 struct dm_thin_device *td; 1122 1123 /* TODO: failure should mark the transaction invalid */ 1124 r = __open_device(pmd, dev, 0, &td); 1125 if (r) 1126 return r; 1127 1128 if (td->open_count > 1) { 1129 __close_device(td); 1130 return -EBUSY; 1131 } 1132 1133 list_del(&td->list); 1134 kfree(td); 1135 r = dm_btree_remove(&pmd->details_info, pmd->details_root, 1136 &key, &pmd->details_root); 1137 if (r) 1138 return r; 1139 1140 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1141 if (r) 1142 return r; 1143 1144 return 0; 1145} 1146 1147int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, 1148 dm_thin_id dev) 1149{ 1150 int r = -EINVAL; 1151 1152 down_write(&pmd->root_lock); 1153 if (!pmd->fail_io) 1154 r = __delete_device(pmd, dev); 1155 up_write(&pmd->root_lock); 1156 1157 return r; 1158} 1159 1160int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, 1161 uint64_t current_id, 1162 uint64_t new_id) 1163{ 1164 int r = -EINVAL; 1165 1166 down_write(&pmd->root_lock); 1167 1168 if (pmd->fail_io) 1169 goto out; 1170 1171 if (pmd->trans_id != current_id) { 1172 DMERR("mismatched transaction id"); 1173 goto out; 1174 } 1175 1176 pmd->trans_id = new_id; 1177 r = 0; 1178 1179out: 1180 up_write(&pmd->root_lock); 1181 1182 return r; 1183} 1184 1185int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, 1186 uint64_t *result) 1187{ 1188 int r = -EINVAL; 1189 1190 down_read(&pmd->root_lock); 1191 if (!pmd->fail_io) { 1192 *result = pmd->trans_id; 1193 r = 0; 1194 } 1195 up_read(&pmd->root_lock); 1196 1197 return r; 1198} 1199 1200static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 1201{ 1202 int r, inc; 1203 struct thin_disk_superblock *disk_super; 1204 struct dm_block *copy, *sblock; 1205 dm_block_t held_root; 1206 1207 /* 1208 * Copy the superblock. 1209 */ 1210 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); 1211 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION, 1212 &sb_validator, ©, &inc); 1213 if (r) 1214 return r; 1215 1216 BUG_ON(!inc); 1217 1218 held_root = dm_block_location(copy); 1219 disk_super = dm_block_data(copy); 1220 1221 if (le64_to_cpu(disk_super->held_root)) { 1222 DMWARN("Pool metadata snapshot already exists: release this before taking another."); 1223 1224 dm_tm_dec(pmd->tm, held_root); 1225 dm_tm_unlock(pmd->tm, copy); 1226 return -EBUSY; 1227 } 1228 1229 /* 1230 * Wipe the spacemap since we're not publishing this. 1231 */ 1232 memset(&disk_super->data_space_map_root, 0, 1233 sizeof(disk_super->data_space_map_root)); 1234 memset(&disk_super->metadata_space_map_root, 0, 1235 sizeof(disk_super->metadata_space_map_root)); 1236 1237 /* 1238 * Increment the data structures that need to be preserved. 1239 */ 1240 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root)); 1241 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root)); 1242 dm_tm_unlock(pmd->tm, copy); 1243 1244 /* 1245 * Write the held root into the superblock. 1246 */ 1247 r = superblock_lock(pmd, &sblock); 1248 if (r) { 1249 dm_tm_dec(pmd->tm, held_root); 1250 return r; 1251 } 1252 1253 disk_super = dm_block_data(sblock); 1254 disk_super->held_root = cpu_to_le64(held_root); 1255 dm_bm_unlock(sblock); 1256 return 0; 1257} 1258 1259int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd) 1260{ 1261 int r = -EINVAL; 1262 1263 down_write(&pmd->root_lock); 1264 if (!pmd->fail_io) 1265 r = __reserve_metadata_snap(pmd); 1266 up_write(&pmd->root_lock); 1267 1268 return r; 1269} 1270 1271static int __release_metadata_snap(struct dm_pool_metadata *pmd) 1272{ 1273 int r; 1274 struct thin_disk_superblock *disk_super; 1275 struct dm_block *sblock, *copy; 1276 dm_block_t held_root; 1277 1278 r = superblock_lock(pmd, &sblock); 1279 if (r) 1280 return r; 1281 1282 disk_super = dm_block_data(sblock); 1283 held_root = le64_to_cpu(disk_super->held_root); 1284 disk_super->held_root = cpu_to_le64(0); 1285 1286 dm_bm_unlock(sblock); 1287 1288 if (!held_root) { 1289 DMWARN("No pool metadata snapshot found: nothing to release."); 1290 return -EINVAL; 1291 } 1292 1293 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©); 1294 if (r) 1295 return r; 1296 1297 disk_super = dm_block_data(copy); 1298 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root)); 1299 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root)); 1300 dm_sm_dec_block(pmd->metadata_sm, held_root); 1301 1302 return dm_tm_unlock(pmd->tm, copy); 1303} 1304 1305int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd) 1306{ 1307 int r = -EINVAL; 1308 1309 down_write(&pmd->root_lock); 1310 if (!pmd->fail_io) 1311 r = __release_metadata_snap(pmd); 1312 up_write(&pmd->root_lock); 1313 1314 return r; 1315} 1316 1317static int __get_metadata_snap(struct dm_pool_metadata *pmd, 1318 dm_block_t *result) 1319{ 1320 int r; 1321 struct thin_disk_superblock *disk_super; 1322 struct dm_block *sblock; 1323 1324 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 1325 &sb_validator, &sblock); 1326 if (r) 1327 return r; 1328 1329 disk_super = dm_block_data(sblock); 1330 *result = le64_to_cpu(disk_super->held_root); 1331 1332 return dm_bm_unlock(sblock); 1333} 1334 1335int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, 1336 dm_block_t *result) 1337{ 1338 int r = -EINVAL; 1339 1340 down_read(&pmd->root_lock); 1341 if (!pmd->fail_io) 1342 r = __get_metadata_snap(pmd, result); 1343 up_read(&pmd->root_lock); 1344 1345 return r; 1346} 1347 1348int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, 1349 struct dm_thin_device **td) 1350{ 1351 int r = -EINVAL; 1352 1353 down_write(&pmd->root_lock); 1354 if (!pmd->fail_io) 1355 r = __open_device(pmd, dev, 0, td); 1356 up_write(&pmd->root_lock); 1357 1358 return r; 1359} 1360 1361int dm_pool_close_thin_device(struct dm_thin_device *td) 1362{ 1363 down_write(&td->pmd->root_lock); 1364 __close_device(td); 1365 up_write(&td->pmd->root_lock); 1366 1367 return 0; 1368} 1369 1370dm_thin_id dm_thin_dev_id(struct dm_thin_device *td) 1371{ 1372 return td->id; 1373} 1374 1375/* 1376 * Check whether @time (of block creation) is older than @td's last snapshot. 1377 * If so then the associated block is shared with the last snapshot device. 1378 * Any block on a device created *after* the device last got snapshotted is 1379 * necessarily not shared. 1380 */ 1381static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time) 1382{ 1383 return td->snapshotted_time > time; 1384} 1385 1386int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, 1387 int can_issue_io, struct dm_thin_lookup_result *result) 1388{ 1389 int r; 1390 __le64 value; 1391 struct dm_pool_metadata *pmd = td->pmd; 1392 dm_block_t keys[2] = { td->id, block }; 1393 struct dm_btree_info *info; 1394 1395 if (pmd->fail_io) 1396 return -EINVAL; 1397 1398 down_read(&pmd->root_lock); 1399 1400 if (can_issue_io) { 1401 info = &pmd->info; 1402 } else 1403 info = &pmd->nb_info; 1404 1405 r = dm_btree_lookup(info, pmd->root, keys, &value); 1406 if (!r) { 1407 uint64_t block_time = 0; 1408 dm_block_t exception_block; 1409 uint32_t exception_time; 1410 1411 block_time = le64_to_cpu(value); 1412 unpack_block_time(block_time, &exception_block, 1413 &exception_time); 1414 result->block = exception_block; 1415 result->shared = __snapshotted_since(td, exception_time); 1416 } 1417 1418 up_read(&pmd->root_lock); 1419 return r; 1420} 1421 1422static int __insert(struct dm_thin_device *td, dm_block_t block, 1423 dm_block_t data_block) 1424{ 1425 int r, inserted; 1426 __le64 value; 1427 struct dm_pool_metadata *pmd = td->pmd; 1428 dm_block_t keys[2] = { td->id, block }; 1429 1430 value = cpu_to_le64(pack_block_time(data_block, pmd->time)); 1431 __dm_bless_for_disk(&value); 1432 1433 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value, 1434 &pmd->root, &inserted); 1435 if (r) 1436 return r; 1437 1438 td->changed = 1; 1439 if (inserted) 1440 td->mapped_blocks++; 1441 1442 return 0; 1443} 1444 1445int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, 1446 dm_block_t data_block) 1447{ 1448 int r = -EINVAL; 1449 1450 down_write(&td->pmd->root_lock); 1451 if (!td->pmd->fail_io) 1452 r = __insert(td, block, data_block); 1453 up_write(&td->pmd->root_lock); 1454 1455 return r; 1456} 1457 1458static int __remove(struct dm_thin_device *td, dm_block_t block) 1459{ 1460 int r; 1461 struct dm_pool_metadata *pmd = td->pmd; 1462 dm_block_t keys[2] = { td->id, block }; 1463 1464 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root); 1465 if (r) 1466 return r; 1467 1468 td->mapped_blocks--; 1469 td->changed = 1; 1470 1471 return 0; 1472} 1473 1474int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block) 1475{ 1476 int r = -EINVAL; 1477 1478 down_write(&td->pmd->root_lock); 1479 if (!td->pmd->fail_io) 1480 r = __remove(td, block); 1481 up_write(&td->pmd->root_lock); 1482 1483 return r; 1484} 1485 1486int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) 1487{ 1488 int r; 1489 uint32_t ref_count; 1490 1491 down_read(&pmd->root_lock); 1492 r = dm_sm_get_count(pmd->data_sm, b, &ref_count); 1493 if (!r) 1494 *result = (ref_count != 0); 1495 up_read(&pmd->root_lock); 1496 1497 return r; 1498} 1499 1500bool dm_thin_changed_this_transaction(struct dm_thin_device *td) 1501{ 1502 int r; 1503 1504 down_read(&td->pmd->root_lock); 1505 r = td->changed; 1506 up_read(&td->pmd->root_lock); 1507 1508 return r; 1509} 1510 1511bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd) 1512{ 1513 bool r = false; 1514 struct dm_thin_device *td, *tmp; 1515 1516 down_read(&pmd->root_lock); 1517 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 1518 if (td->changed) { 1519 r = td->changed; 1520 break; 1521 } 1522 } 1523 up_read(&pmd->root_lock); 1524 1525 return r; 1526} 1527 1528bool dm_thin_aborted_changes(struct dm_thin_device *td) 1529{ 1530 bool r; 1531 1532 down_read(&td->pmd->root_lock); 1533 r = td->aborted_with_changes; 1534 up_read(&td->pmd->root_lock); 1535 1536 return r; 1537} 1538 1539int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result) 1540{ 1541 int r = -EINVAL; 1542 1543 down_write(&pmd->root_lock); 1544 if (!pmd->fail_io) 1545 r = dm_sm_new_block(pmd->data_sm, result); 1546 up_write(&pmd->root_lock); 1547 1548 return r; 1549} 1550 1551int dm_pool_commit_metadata(struct dm_pool_metadata *pmd) 1552{ 1553 int r = -EINVAL; 1554 1555 down_write(&pmd->root_lock); 1556 if (pmd->fail_io) 1557 goto out; 1558 1559 r = __commit_transaction(pmd); 1560 if (r <= 0) 1561 goto out; 1562 1563 /* 1564 * Open the next transaction. 1565 */ 1566 r = __begin_transaction(pmd); 1567out: 1568 up_write(&pmd->root_lock); 1569 return r; 1570} 1571 1572static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd) 1573{ 1574 struct dm_thin_device *td; 1575 1576 list_for_each_entry(td, &pmd->thin_devices, list) 1577 td->aborted_with_changes = td->changed; 1578} 1579 1580int dm_pool_abort_metadata(struct dm_pool_metadata *pmd) 1581{ 1582 int r = -EINVAL; 1583 1584 down_write(&pmd->root_lock); 1585 if (pmd->fail_io) 1586 goto out; 1587 1588 __set_abort_with_changes_flags(pmd); 1589 __destroy_persistent_data_objects(pmd); 1590 r = __create_persistent_data_objects(pmd, false); 1591 if (r) 1592 pmd->fail_io = true; 1593 1594out: 1595 up_write(&pmd->root_lock); 1596 1597 return r; 1598} 1599 1600int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result) 1601{ 1602 int r = -EINVAL; 1603 1604 down_read(&pmd->root_lock); 1605 if (!pmd->fail_io) 1606 r = dm_sm_get_nr_free(pmd->data_sm, result); 1607 up_read(&pmd->root_lock); 1608 1609 return r; 1610} 1611 1612int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, 1613 dm_block_t *result) 1614{ 1615 int r = -EINVAL; 1616 1617 down_read(&pmd->root_lock); 1618 if (!pmd->fail_io) 1619 r = dm_sm_get_nr_free(pmd->metadata_sm, result); 1620 up_read(&pmd->root_lock); 1621 1622 return r; 1623} 1624 1625int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, 1626 dm_block_t *result) 1627{ 1628 int r = -EINVAL; 1629 1630 down_read(&pmd->root_lock); 1631 if (!pmd->fail_io) 1632 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result); 1633 up_read(&pmd->root_lock); 1634 1635 return r; 1636} 1637 1638int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result) 1639{ 1640 int r = -EINVAL; 1641 1642 down_read(&pmd->root_lock); 1643 if (!pmd->fail_io) 1644 r = dm_sm_get_nr_blocks(pmd->data_sm, result); 1645 up_read(&pmd->root_lock); 1646 1647 return r; 1648} 1649 1650int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result) 1651{ 1652 int r = -EINVAL; 1653 struct dm_pool_metadata *pmd = td->pmd; 1654 1655 down_read(&pmd->root_lock); 1656 if (!pmd->fail_io) { 1657 *result = td->mapped_blocks; 1658 r = 0; 1659 } 1660 up_read(&pmd->root_lock); 1661 1662 return r; 1663} 1664 1665static int __highest_block(struct dm_thin_device *td, dm_block_t *result) 1666{ 1667 int r; 1668 __le64 value_le; 1669 dm_block_t thin_root; 1670 struct dm_pool_metadata *pmd = td->pmd; 1671 1672 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le); 1673 if (r) 1674 return r; 1675 1676 thin_root = le64_to_cpu(value_le); 1677 1678 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result); 1679} 1680 1681int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 1682 dm_block_t *result) 1683{ 1684 int r = -EINVAL; 1685 struct dm_pool_metadata *pmd = td->pmd; 1686 1687 down_read(&pmd->root_lock); 1688 if (!pmd->fail_io) 1689 r = __highest_block(td, result); 1690 up_read(&pmd->root_lock); 1691 1692 return r; 1693} 1694 1695static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count) 1696{ 1697 int r; 1698 dm_block_t old_count; 1699 1700 r = dm_sm_get_nr_blocks(sm, &old_count); 1701 if (r) 1702 return r; 1703 1704 if (new_count == old_count) 1705 return 0; 1706 1707 if (new_count < old_count) { 1708 DMERR("cannot reduce size of space map"); 1709 return -EINVAL; 1710 } 1711 1712 return dm_sm_extend(sm, new_count - old_count); 1713} 1714 1715int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1716{ 1717 int r = -EINVAL; 1718 1719 down_write(&pmd->root_lock); 1720 if (!pmd->fail_io) 1721 r = __resize_space_map(pmd->data_sm, new_count); 1722 up_write(&pmd->root_lock); 1723 1724 return r; 1725} 1726 1727int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1728{ 1729 int r = -EINVAL; 1730 1731 down_write(&pmd->root_lock); 1732 if (!pmd->fail_io) 1733 r = __resize_space_map(pmd->metadata_sm, new_count); 1734 up_write(&pmd->root_lock); 1735 1736 return r; 1737} 1738 1739void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd) 1740{ 1741 down_write(&pmd->root_lock); 1742 pmd->read_only = true; 1743 dm_bm_set_read_only(pmd->bm); 1744 up_write(&pmd->root_lock); 1745} 1746 1747void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd) 1748{ 1749 down_write(&pmd->root_lock); 1750 pmd->read_only = false; 1751 dm_bm_set_read_write(pmd->bm); 1752 up_write(&pmd->root_lock); 1753} 1754 1755int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, 1756 dm_block_t threshold, 1757 dm_sm_threshold_fn fn, 1758 void *context) 1759{ 1760 int r; 1761 1762 down_write(&pmd->root_lock); 1763 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context); 1764 up_write(&pmd->root_lock); 1765 1766 return r; 1767} 1768 1769int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd) 1770{ 1771 int r; 1772 struct dm_block *sblock; 1773 struct thin_disk_superblock *disk_super; 1774 1775 down_write(&pmd->root_lock); 1776 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG; 1777 1778 r = superblock_lock(pmd, &sblock); 1779 if (r) { 1780 DMERR("couldn't read superblock"); 1781 goto out; 1782 } 1783 1784 disk_super = dm_block_data(sblock); 1785 disk_super->flags = cpu_to_le32(pmd->flags); 1786 1787 dm_bm_unlock(sblock); 1788out: 1789 up_write(&pmd->root_lock); 1790 return r; 1791} 1792 1793bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd) 1794{ 1795 bool needs_check; 1796 1797 down_read(&pmd->root_lock); 1798 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG; 1799 up_read(&pmd->root_lock); 1800 1801 return needs_check; 1802} 1803 1804void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd) 1805{ 1806 down_read(&pmd->root_lock); 1807 if (!pmd->fail_io) 1808 dm_tm_issue_prefetches(pmd->tm); 1809 up_read(&pmd->root_lock); 1810} 1811